EP 1229526 A3 20040324 - Optical pickup unit with a rotatable phase difference plate
Title (en)
Optical pickup unit with a rotatable phase difference plate
Title (de)
Optische Abtastvorrichtung mit rotierbarer Phasendifferenzplatte
Title (fr)
Tête optique avec plaque à différence de phase pivotante
Publication
Application
Priority
JP 2001021094 A 20010130
Abstract (en)
[origin: EP1229526A2] In an optical pickup unit for converging a laser beam having a predetermined polarization direction produced by a semiconductor laser (LD) on a signal recording face of an optical disc (Disc) through an objective lens (OL), a phase difference plate (PDP) is rotatably disposed before the objective lens around an optical axis. A rotation adjusting mechanism mechanically rotates the phase difference plate around the optical axis by any angle. It is therefore possible to adjust an included angle between a direction of a major axis (K) of a spot and a polarization direction (J) of the laser beam on the signal recording face at any angle. <IMAGE>
IPC 1-7
IPC 8 full level
G02B 5/30 (2006.01); G11B 7/135 (2006.01); G11B 7/1365 (2012.01); G11B 7/22 (2006.01)
CPC (source: EP)
G11B 7/1365 (2013.01); G11B 7/22 (2013.01)
Citation (search report)
- [X] EP 1030296 A2 20000823 - MATSUSHITA ELECTRIC IND CO LTD [JP]
- [X] US 4766303 A 19880823 - YOSHIZUMI KEIICHI [JP], et al
- [X] EP 0908872 A2 19990414 - FUJITSU LTD [JP]
- [X] PATENT ABSTRACTS OF JAPAN vol. 2000, no. 02 29 February 2000 (2000-02-29)
- [X] PATENT ABSTRACTS OF JAPAN vol. 1998, no. 12 31 October 1998 (1998-10-31)
- [DA] PATENT ABSTRACTS OF JAPAN vol. 1999, no. 14 22 December 1999 (1999-12-22)
Designated contracting state (EPC)
AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE TR
DOCDB simple family (publication)
EP 1229526 A2 20020807; EP 1229526 A3 20040324; JP 2002230822 A 20020816
DOCDB simple family (application)
EP 02250640 A 20020130; JP 2001021094 A 20010130